The present invention relates to a rotary board treating apparatus and particularly to an apparatus for soldering printed circuit boards (hereinafter referred to as boards).
Heretofore, the so-called merry-go-round type board treating apparatus has been widely used for treating the boards in a flux bath, a solder bath and a rinsing bath successively. Further, the same type apparatus is known wherein the board is soldered, the solder retained within the through-holes of the board and the excess solder on the board are removed, and the thickness of the solder layer is made uniform successively.
In such board treating apparatuses, since attachment and removal of boards with respect to clamps are effected at the same rotational position, it is difficult to completely automate the transfer and holding of boards, and since a plurality of clamps are carried by the corresponding number of arms extending from a single center shaft, the treating periods of time at the respective positions are the same, with the result that it has been impossible to perform the treatments at the respective positions for varying optimum periods of time for the particular treatments and to lift and lower boards at different speeds. Thus, some of individual treatments must be continued for unnecessary long periods of time until a treatment requiring the longest treating time has been finished.
Accordingly, it is an object of the present invention to provide an automatic board treating apparatus which solves the aforesaid defects and wherein a plurality of treating devices are radially spaced at a constant angle to each other and the necessary immersion periods and lifting and lowering speeds can be independently determined.